Devices which allow an infant to exercise its legs and practice walking have been proposed in the past. For instance, U.S. Pat. No. 4,743,008 discloses an infant exerciser which is horizontally supported by legs in a central opening of an annular tray and a treadmill assembly is suspended from the seat. An infant placed in the seat is thus able to move its legs in a walking motion on the treadmill and is able to change its field of view.
U.S. Pat. No. 839,681 discloses a baby walker in which a seat is slidably mounted on guide rails supported on a stationary frame. A baby seated in the seat can walk from one end of the guide rails to an opposite end on a fastboard or treadway. Such a device, however, is adapted for unidirectional travel only. That is, once the baby reaches the end of the treadway, the seat must be returned to the other end, thereby requiring assistance from older children or adults. Also, the baby cannot turn around or change its field of view while seated.
U.S. Pat. No. 875,377 discloses a baby walker in which a seat is rotatably mounted on a carriage adapted to move back and forth along a pair of support rods. A baby seated in the seat can walk from one of the support rods to the other end on a platform. Once the baby reaches the opposite end of the platform, he or she can turn the seat around and then walk back to the other end. Because the baby actually walks in a rectilinear fashion along the platform, the baby walker is, out of necessity, comparatively large and cumbersome. Although the mobility of the baby walker is enhanced by trucks (i.e., roller assemblies) provided at the bottom of the walker, such mobility poses a potential hazard in that the walker can be accidentally or unintentionally moved close to stairs or dangerous appliances, such as stoves and heaters.
U.S. Pat. No. 3,127,170 discloses a children's play table with a chair attached to a base. The chair can rotate about the central vertical axis of the table. However, because the chair is secured to a horizontal support rod by screws, the chair is prevented from rotating or spinning about an axis of rotation passing through the center of the chair. Also, while an infant seated in the chair is able to pull and push the chair around the table, the infant can not actually walk while seated in the chair.